The production of the charm-strange baryon $\Xi_{\rm c}^0$ is measured for the first time at the LHC via its semileptonic decay into e$^+\Xi^-\nu_{\rm e}$ in pp collisions at $\sqrt{s}=7$ TeV with the ALICE detector. The transverse momentum ($p_{\rm T}$) differential cross section multiplied by the branching ratio is presented in the interval 1 $<~$ $p_{\rm T}$ $<~$ 8 GeV/$c$ at mid-rapidity, $|y|$ $<~$ 0.5. The transverse momentum dependence of the $\Xi_{\rm c}^0$ baryon production relative to the D$^0$ meson production is compared to predictions of event generators with various tunes of the hadronisation mechanism, which are found to underestimate the measured cross-section ratio.
Phys. Lett. B 781 (2018) 8-19
HEP Data
e-Print: arXiv:1712.04242 | PDF | inSPIRE
CER-EP-2017-332
Figure 1
(a) Invariant-mass distribution of $\Xi^- \rightarrow \pi^-\Lambda$ (and charge conjugate) candidates integrated over \pt. The arrow indicates the world average $\Xi^-$ mass from Ref. and the dashed lines indicate the selected interval. (b) Invariant-mass distributions of right-sign and wrong-sign (and charge conjugate) pairs integrated over the whole \pt\ interval. The arrow indicates the \xicz\ mass . |  |
Figure 4
Inclusive \xicz-baryon \pt-differential production cross section multiplied by the branching ratio into ${\rm e}^+\Xi^-\nu_{\rm e}$, as a function of \pt\ for $|y|< 0.5$, in \pp collisions at $\sqrt{s} =$ 7 TeV. The error bars and boxes represent the statistical and systematic uncertainties, respectively. The contribution from \xib\ decays is not subtracted. |  |
Figure 5
Ratio of the \pt-differential cross sections of \xicz\ baryons (multiplied by the branching ratio into ${\rm e}^+\Xi^-\nu_{\rm e}$) and \Dzero mesons as a function of \pt\ for $|y|< 0.5$, in \pp collisions at $\sqrt{s} = $ 7 TeV. The error bars and boxes represent the statistical and systematic uncertainties, respectively. Predictions from theoretical models, (a) {\sc pythia 8} with different tunes (b) {\sc dipsy} and {\sc herwig 7} , are shown as shaded bands representing the range of the currently available theoretical predictions for the branching ratio of the considered \xicz\ decay mode. |  |
